But confusion arose even after the launch, when it emerged that the Apple Watch was not going to be actually in stock in any store for the foreseeable future. It was only available to buy online — but even those who did order it through Apple's website were told their orders could take weeks or even months to arrive. Meanwhile, Apple Store staff were overwhelmed with questions from confused customers, unable to understand why Apple's shiny new gadget wasn't actually available to buy anywhere.

We finally have answers as to how this happened — and it's not just demand outstripping supply.

It's not Ahrendts' fault, either.

Instead, it's down to a technical fault in the "Taptic engine" provided by AAC Technologies Holdings. The taptic engine is what provides vital feedback and notifications to the wearable through vibrations — but AAC's components have been found to be defective, breaking down over time.

AAC has now been dropped — and Apple's other taptic engine supplier, Nidec Corp., has been forced to take on the full load of production. But it isn't able to ramp up its output immediately, causing delays in the supply chain. These delays translated into a lack of stock, producing the subsequent problems we've seen.